Cylinder Liner; Cylinder Liner - Endoscopic Examination - MTU 12V4000C Series Operating Instructions Manual

8.2 Cylinder Liner

8.2.1 Cylinder liner – Endoscopic examination
Preconditions
☑ Engine is stopped and starting disabled
Special tools, Material, Spare parts
Designation / Use
Barring tool
Ratchet with extension
Endoscope
Preparatory steps
1. Remove cylinder head cover (→ Page 94).
2. Remove injector (→ Page 97).
Positioning crankshaft at BDC
1. Using barring tool, turn crankshaft until crankshaft journal of the cylinder to be tested has reached BDC.
2. Insert endoscope into cylinder liner through injector seat.
Endoscopic examination of cylinder liner
Findings
• Thin carbon coating around carbon scraper ring
• Slight localized additive deposits at top edge
• Localized smooth areas at bottom edge
• Carbon deposits on entire circumference between top piston ring and
bottom edge of carbon scraper ring
• First signs of marks left by top piston ring
• Bright mark on entire circumference
• Faultless, even honing pattern
• First signs of marks left by lower cooling bores
• Running pattern seems darker
• Dark areas with even or varying degrees of discoloration
• Beginning and end of the discoloration are not sharply defined and do
not cover the entire stroke area
• Dark areas in the upper section of the cooling bore, remaining circum-
ference are faultless
• Piston rings are faultless
• On the entire circumference, apart from light areas of discoloration (do
not impair operation) clearly darker stripes that start at the top piston
ring
• Heat discoloration in the direction of stroke and honing pattern dam-
age
• Heat discoloration of piston rings
Part No.
F6555766
F30006212
Y20097353
Measure
No actions required.
Further endoscopic examina-
tion required as part of mainte-
nance work.
Cylinder liner must be replaced,
contact Service.
MS150049/04E 2017-04 | Cylinder Liner | 77
Qty.
1
1
1